厄尔尼诺时期北部湾表层水温和盐度的异常

ANOMALIES OF SEA SURFACE TEMPERATURE AND SALINITY IN BEIBU GULF DURING EL NIO EVENTS

本文利用北部湾涠洲岛水文站(109°07′E,21°01′N)1960—1982年间的观测资料,阐明海表面温度 (SST)和盐度的年际变化。在1960—1982年期间,北部湾海表层温度,呈现出明显的异常暖事件。在此期间,除1982年外,在该海湾共发生5次与厄尔尼诺(El Nio)相关联的暖事件。其中,1965—1966年和1972—1973年是两次大的暖事件,而其余的3次为中强度的。快速傅里叶变换(FFT)得到的SST异常的一个谱,呈现一个峰,其对应的周期相当于37个月。在该海湾,表层盐度异常也明显地与厄尔尼诺事件有关联。

Hydrographic data observed from 1960-1982 at Weizhou Island Observatory (109°07'E, 21°01'N) in Beibu Gulf were used to describe the interan nual variations of sea surface temperature (SST) and salinity. Some striking anomalies of SST and sea surface salinity appeared in the Gulf during the period of 1960-1982. Except for 1982,warm events associated with El Nino event during this period occurred in 1963, 1965-1966, 1968-1969, 1972-1973 and 1976-1977. Among them there were two major warm events during 1965-1966 and 1972-1973. The three others were moderate. A spectrum of monthly mean SST anomalies performed by using Fast Fourier Transform (FFT) exhibited a peak with a period of 37 months. In the Gulf, sea salinity anomalies also apparently associated with El Nino events. During the El Nino, the salinities were highest and anomalies were largest.Usually, the early stages of El Nino were characterized by low salinities. Contrary, the late stages were characterized by high salinities. Generally interannual variations of SST and sea surface salinity in the Gulf correlated mainly with the El Nino events.